Switch stack assembly



y 20, 1941- E. J. GLENNON 2,242,971

SWITCH STACK ASSEMBLY Filed Jan. 10, 1941 Patented May 20, 1941 SWITCHSTACK A8! Edward Joseph Gienncn, Chicago, Ill. aasignor Electric toOcular tionoflllinois Chim 1 Application January 10, 1941, Serial No.378,861

(Cl. zoo-ice) liclaima assembly of insulating spacers and ako throughholes in the switch blades aligned with the holes in the insulatingspacers. The assembly or stack or insulating spacers or punchings isusually built up by a hand operation, but such assembly is not always atonce permanently mounted on the support, it being common practice toassemble the switch stacks for shipment or other utilization before theattaching screws are permanently afiixed.

A problem arises in shippins the assembled. but unmounted switch stacksbecause the spacing insulators and switch blades tend to work oil. theinsulating sleeves by jarring and handling and it becomes necessary tocollect the relatively small and assemble them, all of which entailsloss of time and annoyance to the manufacturer or user. In order .toovercome this problem various xpedient-ties have been resorted to,including, among others, the application of glue or adhesive to theinsulating spacers or punchings to hold the same together in assembledrelation. the use of a wire tie through the sleeve as a binder, or theuse of rubber bands around the stack assembly. All of these expedienciesincrease the cost in handling and assembling the stacks and on smallitems of this class every slight increase in cost is a matter of greatconcern.

The aforementioned invention overcomes the difiiculties in maintainingthe switch stacks in assembled relation in a manner which does not addany appreciable increment to the manufacturing cost, as will appearhereinafter.

It is therefore a principal object of the invention to provide means formaintaining a switch stack assembly in assembled condition for purposesof handling and shipping without resort to gluing, binding or otherexpediencies likely to add to the manufacturing cost.

A further and more specific object of the invention is the provision ofmeans for maintaining a switch stack assembly in assembled condition forpurposes of handling and the like, said means including a provision ofinsulator stack punchings having undersized sleeve holes with specialslot formations to permit expansion for engagement with the sleeving ina tight fit whereby the assembled stack is prevented from falling apartprior to permanent installation.

A further object of the invention is the provision of switch stackinsulator punchings including one or more holes for e of an insulatingsleeve having a diameter slightly larger than said holes, and expansionformations adjoining said holes to permit forcing the punchings intoassembled relation with the sleeves with a sufiiciently tight fit toassure against accidental disassembly of the stack in handling orshipping prior to permanent installation.

Other objects, advantages and novel aspects of the invention reside incertain details of construction as well as the cooperative relationshipof the component parts of the illustrative embodiment describedhereinafter in view of the annexed drawing. in which:

Fig. 1 is an exploded perspective of a switch stack assembly.

Fig. 2 is a top plan view of one form of improved insulator punching.

Fig. 3 is a top plan view of a modified form of insulator punching orspacer.

Fig. 4 is another modified form of insulator punching or spacer.

Fig. 5 is a top plan view of a further modified form of insulator spaceror punching.

Fig. 6 is an enlarged fragment of the preferred form of insulatorpunching or spacer aligned with an insulating sleeve prior to assembly.

In Fig. l of the drawing herein there is shown to enlarged scale aswitch stack structure in assembled condition and in relation to a.mounting bracket preparatory to the application of the mounting screwsor other means for permanently afiixing the switch structure on itsultimate carrying base.

In the foregoing arrangement there are included a pair of switch bladesI0 and II of elongated form and constructed of a suitable electroconductive springy material, each blade including near one end asuitable contact point its and Ho respectively, and near the oppositeend a soldering lug or .tail lb and llb respectively. Said blades aremaintained in a normal condition of separation by means of one or morespacers i2 and II of insulating material such as fiber, Bakelite or thelike, and there are an additional number of spacers or punchings N andII tively adapted to thread into a corresponding tapped hole I90. or20a. in bracket 16.

To properly align the several punched holes in the separators orinsulating spacers, and also to prevent contact between the mountingscrews and the edge portion of the holes in the switch blades, there areprovided insulating sleeves in the form of fiber or hard rubber tubingdimensioned to fit into the aligned holes with their respective oppositeends flush with the outer surfaces of the outermost spacers orpunchings. Thus the insulating sleeves 2i and 22 prevent any electricalcontact between the blades and the mounting screws.

In the manufacture of various devices in which such switch assembliesare used such as relays, the stacks are not built up on the mountingbracket l6, but are assembled as stacks. that is to say, as a unitconsisting of the blades I and II the plurality of spacers l2-l5, andthe sleeves 2| and 22. These stack units are then delivered in quantityto assemblers who mount them on the various devices, or the stacks areshipped to other manufacturers for ultimate assembly in some kind ofmechanism.

In order to keep the stacks from falling apart, the hereinbeforedescribed expediencies of gluing, binding, etc. must be resorted to.

The present invention overcomes the prior difficulties by modifying thetop and bottom spacers or punchings as follows: Considering for examplethe .top punching ll shown in plan view in Fig. 2, the customary twoholes Ila and Ho are punched in the strip or spacer, but as illustratedto enlarge scale in Fig. 6, these holes are made slightly undersized indiameter relative to the diameter DI, outside dimension of theinsulating sleeve or tube 2|. In other words the diameter of thepunchings or hole as indicated at D2 in Fig. 6 is less than the outsidediameter DI, so that ordinarily the sleeve could not be passed throughthe hole Ila in the punching.

To permit fitting the outside spacers with the undersized holes ontotheir respective sleeve portions 2| and 22 the top and bottom spacerpunch- 23a and 231) out into the opposite lateral edge portion of thespacer l1 and each communicating into the correspondingly adjacent holeIla or I'll).

The amount of undersize in the spacer punchings in general depends uponthe other dimensions of the piece in any given case. In the exampleshown the spacers or punchings are preferably three-quarters of an inchlong by threeeighths inch wide and one-sixteenth to onethirty-secondinch thick. Under these circumstances the difference in diameter betweenthe holes and the fiber or rubber sleeving may be two to threethousandths inch. At the bottom of Fig. 6 this difference is indicatedas Dl D2 by 0.002" to 0.003".

In Fig. 3 the spacer or punching Ila: is substantially the same as thatdescribed in view of Fig. 2 except that the notches 23:1: leading intothe sleeve holes are situated on opposite sides of the strip along thelong edge thereof. This may be advantageous where particularly thinpieces of insulating material are employed and it is desired to limitthe amount of give when the hole expands to engage the sleeve.

In Fig. 4 the modified spacer or punching l'lu differs from thoseheretofore described in that a central elongated slip 2311 is employedto join the two sleeve holes to permit yieldability in engaging thesleeve.

According to the arrangement of Fig. 5, the spacer or punching I12 haseach of its sleeve holes provided with a short radial notch 232 topermit limited expansion, especially where the thickness of theinsulating strip from which the spacer is punched is slight.

In cases where the stock from which the specers or punchings are stampedis thick enough, it is possible to use only top and bottom spacers orpunchings having undersized holes and expansion notches. However, forpurposes of uniformity in production it is preferred to make all spacersor punchings in the manner illustrated in Fig. l for example, whereineach spacer or punching is provided with undersized holes for thesleeves and with formation permitting expension of the hole when forcedonto the sleeve. In this manner each spacer or punching grips the sleeveportion firmly and the entire assembly is thus very securely heldtogether.

While the foregoing description is directed toward the constructionillustrated, I desire it to be understood that I reserve the privilegeof resorting to all of the mechanical changes of which the device issusceptible without departing from the spirit of the invention as to thebeneficial objects sought to be attained, the invention being definedand limited only by the terms 01' the appended claims.

Having thus described my invention, what I claim and desire toprotect'by Letters Patent of the United States is:

1. In a switch stack assembly substantially as described, insulatorpunchings having one or more holes to accommodate an insulating sleeve,said holes being of lesser diameter than the outside diameter of saidsleeve, and formations communicating with said holes permittingexpansion of the same to fit onto said sleeve tightly and thereby holdsaid stack in assembled condition for purposes of handling and the like.

2. In a switch stack assembly including insulating sleeve portions uponwhich insulating spacers are fitted, spacers provided with holes oflesser diameter than the sleeve portions on which'they are to be fitted,said holes having cutaway portions communicating into an edged portionof the spacer whereby to permit expansion of the hole for a tight fitupon the sleeve portion as aforesaid to hold the stack in assembledcondition for purposes of handling and the like.

3. An insulating spacer for use in a. switch stack assembly of the typeincluding an insulating sleeve passed through a stack of insulatingspacers, said spacer including a hole to engal said insulating sleeve,said hole being 0! lesser diameter than the outside diameter of thesleeve upon which it is to engage, and means including a cutaway portionleading into the edge or said hole to permit expansion of the same fortightly fitting upon the sleeve.

4. In a switch stack assembly, insulating spacers having sleeve holeswith formations for expanslon, said spacers being iorcibly fitted uponsleeve portions which are oversize relative to the normal unexpandedcondition oi said sleeve holes, whereby the stack is maintained inassembled condition.

5. In a switch stack assembly of the type ineluding a plurality ofspacer elements arranged in a stack with one or more contact elementsdisposed between any adjacent spacer elements, and a sleeve memberpassing through holes in said spacer and contact elements, I claim thatimprovement which consists in keeping all of said elements in assembledrelation for purposes of handling, transport, and the like, by theprowl. slon oi a gripping flt between said sleeve member or members andthe outermost ones, at least, of said spacer elements by having thesleeve oi larger diameter than the said holes through which the sleevemember or members are passed asai'oresald.

EDWARD JOSEPH GLENNON.

